<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <button id="btn">发消息</button>
    <button id="btn2">关闭连接</button>
    <script>
        // 通过websocket 完成前后端通信
        // 1、建立连接
        const ws = new WebSocket("wss://javascript.info/article/websocket/demo/hello");
        // 2、监听连接成功
        ws.onopen = () => {
            console.log('连接成功');

        };
        // 3、如何发消息
        document.querySelector('#btn').addEventListener = ('click', () => {
            ws.send('你好 websocket 服务器')
        })
        // 4、如何接消息
        ws.onmessage = (event) => {
            console.log('服务端发的消息', event);

        };
        // 5、如何关闭
        document.querySelector('#btn2').addEventListener = ('click', () => {
            ws.close()
        })
        // 6、监听通信关闭
        ws.onclose = () => {
            console.log('连接关闭');
        };





    </script>
</body>

</html>